This content was originally published by the Longmont Observer and is licensed under a Creative Commons license.
The Winter Weather Advisory continues (in this early post)
Winter Weather Advisory
Issued: 10:33 AM Mar. 2, 2019 – National Weather Service
...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 11 AM MST SUNDAY...
* WHAT...Snow expected, becoming heaviest this evening. Total snow accumulations of 4 to 8 inches.
* WHERE...Boulder and the western suburbs of Denver, Greeley, Denver and Castle Rock.
* WHEN...From 9 AM Saturday to 11 AM MST Sunday.
* ADDITIONAL DETAILS...Travel could be very difficult. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Winter Weather Advisory for snow means periods of snow will cause primarily travel difficulties. Expect snow covered roads and limited visibilities, and use caution while driving. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1.
Forecast Discussion:
I'm posting Sunday's post as the arctic front is just entering Colorado Saturday early afternoon. We've already had 2 1/2 inches of snow in NE Longmont with the first couple of upper level waves. I've drawn the 10°F isotherm (line of equal temperature) in Figure 1 to roughly illustrate the advancing cold push of the main front.
The HRRR (Figure 2) paints Longmont with 3-4 inches of new snow by 1 am Mountain Time (as far out as this high resolution map goes). Snow will continue on to sunrise with more snow later Sunday afternoon. You can see the first and second punches in Figure 3. This all tapers off later Sunday night.
It will get pretty blustery this afternoon (Saturday) as the front moves in and temperatures will drop from near freezing Saturday morning to about 15°F by midnight then almost to zero by sunrise. The temperatures will drop and drop. The wet roads will ice over and the snow that falls will come down fluffier and fluffier.
The storm snowfall roundup:
The GFS in Figure 4 gives us 4-5 new inches through Monday am.
The GEM in Figure 5 give us 3-4 more inches through Monday am.
And finally, the NAM gives us a more impressive 4-6 inches for this time period.
The longer range forecast:
As we've said, over the last few days, we get above freezing midday Wednesday. There is a small chance of snow showers Wednesday night then a more focused storm Friday pm and Saturday am.
